Like many Plains Indian tries, the Kansa Believed that each human being
had dual spirits-the wanagi, which lived inside a person, and the nagi,
which lived outside a person and guided and cared for him or her.  When a
brave died, the wanagi lingered, and those living tried to please it by
showing respect for the body that housed it.  After a few days, the nagi
would come and guide the wanagi to the afterworld of the spirits.  Because
the Kansa believed that horse and rider were essentially one being in the
heat of battle, the brave's horse was killed and placed in the grave
beside the dead warrior.